Create Ortho Corrected Raster Dataset (Data Management)

Summary

Creates an orthocorrected raster dataset using a digital elevation model (DEM) and control data to accurately align imagery.

Usage

  • For a more accurate result, use the DEM option for elevation. Use a DEM in the orthocorrection process to correct geometric errors caused by relief displacement.

  • Using a constant elevation value for the Orthorectification Type parameter will not yield accurate results and should only be used when no DEM is available and approximate spatial accuracy is acceptable.

  • You can save the output to BIL, BIP, BMP, BSQ, DAT, Esri Grid, GIF, IMG, JPEG, JPEG 2000, PNG, TIFF, MRF, or CRF format, or any geodatabase raster dataset.

  • If using satellite data, RPCs require a DEM referenced to ellipsoidal heights, but most elevation data (such as USGS NED and ArcGIS Online World Elevation) are referenced to sea level orthometric heights. Check the Geoid parameter (Geoid = "GEOID" in Python) to orthorectify with RPCs unless the DEM is referenced to an ellipsoidal height.

Parameters

LabelExplanationData Type
Input Raster

The raster dataset or mosaic dataset that will be orthorectified.

Raster Dataset; Mosaic Dataset; Mosaic Layer; Raster Layer
Output Raster Dataset

The name, location, and format of the dataset that will be created.

When storing the raster dataset in a file format, specify the file extension as follows:

  • .bilEsri BIL
  • .bipEsri BIP
  • .bmp—BMP
  • .bsqEsri BSQ
  • .dat—ENVI DAT
  • .gif—GIF
  • .img—ERDAS IMAGINE
  • .jpg—JPEG
  • .jp2—JPEG 2000
  • .png—PNG
  • .tif—TIFF
  • .mrf—MRF
  • .crf—CRF
  • No extension for Esri Grid

When storing a raster dataset in a geodatabase, do not add a file extension to the name of the raster dataset.

When storing a raster dataset to a JPEG format file, a JPEG 2000 format file, or a geodatabase, you can specify a Compression Type value and a Compression Quality value in the geoprocessing environments.

Raster Dataset
Orthorectification Type

Specifies whether the orthorectification type will be a DEM or a specified value that represents the average elevation across the image.

  • Constant elevationA specified elevation value will be used.
  • DEMA specified digital elevation model raster will be used.
String
Constant Elevation (Meters)

The constant elevation value that will be used when the Orthorectification Type parameter is Constant elevation.

If a DEM is used in the orthocorrection process, this parameter value is not used.

Double
DEM Raster
(Optional)

The DEM raster that will be used for orthorectification when the Orthorectification Type parameter is DEM

Raster Dataset; Mosaic Dataset; Mosaic Layer; Raster Layer; Image Service
Z Factor
(Optional)

The scaling factor that will be used to convert the elevation values in the DEM.

If the vertical units are meters, set the parameter to 1. If the vertical units are feet, set the parameter to 0.3048. If any other vertical units are used, use this parameter to scale the units to meters.

Double
Z Offset
(Optional)

The base value that will be added to the elevation value in the DEM. This can be used to offset elevation values that do not start at sea level.

Double
Geoid
(Optional)

Specifies whether the geoid correction required by RPCs that reference ellipsoidal heights will be made. Most elevation datasets are referenced to sea level orthometric heights, so this correction is required in these cases to convert to ellipsoidal heights.

  • Unchecked—No geoid correction will be made. Use this option only if the DEM is already expressed in ellipsoidal heights.
  • Checked—A geoid correction will be made to convert orthometric heights to ellipsoidal heights (based on EGM96 geoid).
Boolean

arcpy.management.CreateOrthoCorrectedRasterDataset(in_raster, out_raster_dataset, Ortho_type, constant_elevation, {in_DEM_raster}, {ZFactor}, {ZOffset}, {Geoid})
NameExplanationData Type
in_raster

The raster dataset or mosaic dataset that will be orthorectified.

Raster Dataset; Mosaic Dataset; Mosaic Layer; Raster Layer
out_raster_dataset

The name, location, and format of the dataset that will be created.

When storing the raster dataset in a file format, specify the file extension as follows:

  • .bilEsri BIL
  • .bipEsri BIP
  • .bmp—BMP
  • .bsqEsri BSQ
  • .dat—ENVI DAT
  • .gif—GIF
  • .img—ERDAS IMAGINE
  • .jpg—JPEG
  • .jp2—JPEG 2000
  • .png—PNG
  • .tif—TIFF
  • .mrf—MRF
  • .crf—CRF
  • No extension for Esri Grid

When storing a raster dataset in a geodatabase, do not add a file extension to the name of the raster dataset.

When storing a raster dataset to a JPEG format file, a JPEG 2000 format file, or a geodatabase, you can specify a Compression Type value and a Compression Quality value in the geoprocessing environments.

Raster Dataset
Ortho_type

Specifies whether the orthorectification type will be a DEM or a specified value that represents the average elevation across the image.

  • CONSTANT_ELEVATIONA specified elevation value will be used.
  • DEMA specified digital elevation model raster will be used.
String
constant_elevation

The constant elevation value that will be used when the Ortho_type parameter is CONSTANT_ELEVATION.

If a DEM is used in the orthocorrection process, this parameter value is not used.

Double
in_DEM_raster
(Optional)

The DEM raster that will be used for orthorectification when the Ortho_type parameter is DEM.

Raster Dataset; Mosaic Dataset; Mosaic Layer; Raster Layer; Image Service
ZFactor
(Optional)

The scaling factor that will be used to convert the elevation values in the DEM.

If the vertical units are meters, set the parameter to 1. If the vertical units are feet, set the parameter to 0.3048. If any other vertical units are used, use this parameter to scale the units to meters.

Double
ZOffset
(Optional)

The base value that will be added to the elevation value in the DEM. This can be used to offset elevation values that do not start at sea level.

Double
Geoid
(Optional)

Specifies whether the geoid correction required by RPCs that reference ellipsoidal heights will be made. Most elevation datasets are referenced to sea level orthometric heights, so this correction is required in these cases to convert to ellipsoidal heights.

  • NONENo geoid correction will be made. Use NONE only if the DEM is already expressed in ellipsoidal heights.
  • GEOIDA geoid correction will be made to convert orthometric heights to ellipsoidal heights (based on EGM96 geoid).
Boolean

Code sample

CreateOrthoCorrectedRasterDataset example 1 (Python window)

This is a Python sample for the CreateOrthoCorrectedRasterDataset function.

import arcpy
arcpy.CreateOrthoCorrectedRasterDataset_management("c:/data/RPCdata.tif",
                                                   "c:/data/orthoready.tif",
                                                   "DEM", "#", "c:/data/DEM.img",
                                                   "#", "10", "GEOID")
CreateOrthoCorrectedRasterDataset example 2 (stand-alone script)

This is a Python script sample for the CreateOrthoCorrectedRasterDataset function.

##====================================
##Create Ortho Corrected Raster Dataset
##Usage: CreateOrthoCorrectedRasterDataset_management in_raster out_raster_dataset
##                                                    CONSTANT_ELEVATION | DEM constant_ elevation
##                                                    in_DEM_raster {ZFactor} {ZOffset} {NONE | GEOID}

import arcpy
arcpy.env.workspace = "C:/Workspace"

##Ortho correct with Constant elevation
arcpy.CreateOrthoCorrectedRasterDataset_management("ortho.img", "orthoready.tif",\
                                                   "CONSTANT_ELEVATION", "30", "#",\
                                                   "#", "#", "#")

##Ortho correct with DEM image and Z factors
arcpy.CreateOrthoCorrectedRasterDataset_management("ortho.img", "orthoready_dem.tif",\
                                                   "DEM", "#", "dem.img", "#", "10", "GEOID")

Licensing information

  • Basic: Yes
  • Standard: Yes
  • Advanced: Yes

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